The present invention relates to the measurement of certain physical properties of gases to support the determination of the absolute pressure of a gas. U.S. Pat. No. 4,682,503 dated Jul. 28, 1987 and assigned to Honeywell Inc. describes the use of a microscopic size thermal conductivity-type absolute pressure sensor fabricated on a silicon chip. The sensor includes an elongated V-groove anistropically etched in the silicon with a heated silicon nitride bridge element extending over the surface of the V-groove. U.S. Pat. No. 4,682,503 describes the response of the pressure sensor to air and is not concerned with the variation in sensed absolute pressure due to the composition of the gas being sensed. Applications for accurate absolute pressure readings require that the response of this sensor be compensated for the composition of the specific gas being used.
A need exists in the field of gas measurements for a method of determining the absolute pressure P of a gas which is independent of the makeup or composition of that gas.